Tire tread wear on the edges of a tire will typically indicate inflation pressures are lower than specified.
Under inflation occurs when there is more wear on the edges of the tire. A tire is said to be under-inflated whe the contact patch grows and outside edges of the patch takes on the load.
Tire feathering or scuffing is the indicator of excessive positive or negative toe angle that can be detected by stroking your fingertips over the edge of each tread block. A feather edge on the inside of the tread bar shows excess toe-in, whereas a feather edge on the outside of the tread bar shows toe-out. Changes in camber and caster angle affects the toe angle. Changes in suspension height can also affect the toe angle geometry.
